"Almost all the children you hear of dragged out of pools, if their heart has stopped beating, they either die or have very severe brain damage."

But doctors found Sarah's temperature had dropped to 28 degrees - the temperature to which patients undergoing heart surgery are cooled to slow blood flow. In effect, Sarah's oxygen consumption was so low she was in a state of suspended animation.

"When we took her temperature and found out how cold she was, we forged ahead," Dr Walker said.

"Because she's small she lost heat very rapidly, and her heart probably stopped because she was cold rather than lack of oxygen."

Staff at the Monash Medical Centre yesterday described the toddler's recovery as a miracle. Dr Walker said it was more a case of "freakish good luck" that the water was so cold.

Sarah's father Jeff praised the quick response times of firefighters and paramedics, who worked together under the Emergency Medical Response program.

People wishing a free lesson in CPR can call 1800 77 2001, or phone the Metropolitan Ambulance Service on 9840 3537 for a full first-aid course.